Iva xanthiifolia leaf extract reduced the diversity of indigenous plant rhizosphere bacteria.

BACKGROUND: Iva xanthiifolia, native to North America, is now widely distributed in northeastern China and has become a vicious invasive plant. This article aims to probe the role of leaf extract in the invasion of I. xanthiifolia. METHODS: We collected the rhizosphere soil of Amaranthus tricolor and Setaria viridis in the invasive zone, the noninvasive zone and the noninvasive zone treated with extract from I. xanthiifolia leaf, and obtained I. xanthiifolia rhizosphere soil in the invasive zone. All wild plants were identified by Xu Yongqing. I. xanthiifolia (collection number: RQSB04100), A. tricolor (collection number: 831,030) and S. viridis (collection number: CF-0002-034) are all included in Chinese Virtual Herbarium ( https://www.cvh.ac.cn/index.php ). The soil bacterial diversity was analyzed based on the Illumina HiSeq sequencing platform. Subsequently, taxonomic analysis and Faprotax functional prediction were performed. RESULTS: The results showed that the leaf extract significantly reduced the diversity of indigenous plant rhizosphere bacteria. A. tricolor and S. viridis rhizobacterial phylum and genus abundances were significantly reduced under the influence of I. xanthiifolia or its leaf extract. The results of functional prediction showed that bacterial abundance changes induced by leaf extracts could potentially hinder nutrient cycling in native plants and increased bacterial abundance in the A. tricolor rhizosphere related to aromatic compound degradation. In addition, the greatest number of sensitive Operational Taxonomic Units (OTUs) appeared in the rhizosphere when S. viridis was in response to the invasion of I. xanthiifolia. It can be seen that A. tricolor and S. viridis have different mechanisms in response to the invasion of I. xanthiifolia. CONCLUSION: I. xanthiifolia leaves material has potential role in invasion by altering indigenous plant rhizosphere bacteria.

[Identification of key enzyme genes involved in biosynthesis pathways of lignan and lignin in Eucommia ulmoides based on transcriptome assembly].

Lignan is the main medicinal component of Eucommia ulmoides, and lignin is involved in the defense of plants against diseases and insect pests.They are synthesized from coniferyl alcohol with the help of dirigent(DIR) and peroxidase(POD), respectively.In this study, transcriptome assembly of stems and leaves of E.ulmoides was performed, yielding 112 578 unigenes.Among them, 70 459 were annotated in seven databases.A total of 59 unigenes encodes 11 key enzymes in the biosynthesis pathways of lignin and lignin, of which 11 encode POD and 8 encode DIR.A total of 13 unigenes encoding transcription factors are involved in phenylpropanoid metabolism. Compared with leaves of E.ulmoides, 7 575 unigenes were more highly expressed in stems, of which 462 were involved in phenylpropanoid biosynthesis.Our results extend the public transcriptome dataset of E.ulmoides, which provide valuable information for the analysis of biosynthesis pathways of lignan and lignin in E.ulmoides and lay a foundation for further study on the functions and regulation mechanism of key enzymes in lignan and lignin biosynthesis pathways.

Comparative transcriptomic analysis reveals the regulatory mechanisms of catechins synthesis in different cultivars of Camellia sinensis.

Camellia sinensis (L.) O. Kuntze is used to produce tea, a beverage consumed worldwide. Catechins are major medically active components of C. sinensis and can be used clinically to treat hyperglycaemia, hypertension, and cancer. In this study, we aimed to identify the genes involved in catechins biosynthesis. To this end, we analysed transcriptome data from two different cultivars of C. sinensis using DNBSEQ technology. In total,47,717 unigenes were obtained from two cultivars of C. sinensis, of which 9429 were predicted as new unigenes. In our analyses of the Kyoto Encyclopedia of Genes and Genomes database, 212 unigenes encoding 13 key enzymes involved in catechins biosynthesis were identified; the structures of leucoanthocyanidin reductase and anthocyanidin reductase were spatially modelled. Some of these key enzymes were verified by real-time quantitative polymerase chain reaction, and multiple genes encoding plant resistance proteins or transcription factors were identified and analysed. Furthermore, two microRNAs involved in the regulation of catechins biosynthesis were explored. Differentially expressed genes involved in the flavonoid biosynthesis pathway were identified from pairwise comparisons of genes from different cultivars of tea plants. Overall, our findings expanded the number of publicly available transcript datasets for this valuable plant species and identified candidate genes related to the biosynthesis of C. sinensis catechins, thereby establishing a foundation for further in-depth studies of catechins biosynthesis in varieties or cultivars of C. sinensis.

[Identification of key enzyme genes involved in biosynthesis of steroidal saponins and analysis of biosynthesis pathway in Polygonatum cyrtonema].

Steroidal saponins, which are the characteristic and main active constituents of Polygonatum, exhibit a broad range of pharmacological functions, such as regulating blood sugar, preventing cardiovascular and cerebrovascular diseases and anti-tumor. In this study, we performed RNA sequencing(RNA-Seq) analysis for the flowers, leaves, roots, and rhizomes of Polygonatum cyrtonema using the BGISEQ-500 platform to understand the biosynthesis pathway of steroidal saponins and study their key enzyme genes. The assembly of transcripts for four tissues generated 129 989 unigenes, of which 88 958 were mapped to several public databases for functional annotation, 22 813 unigenes were assigned to 53 subcategories and 64 877 unigenes were annotated to 136 pathways in KEGG database. Furthermore, 502 unigenes involved in the biosynthesis pathway of steroidal saponins were identified, of which 97 unigenes encoding 12 key enzymes. Cycloartenol synthase, the first key enzyme in the pathway of phytosterol biosynthesis, showed conserved catalytic domain and substrate binding domain based on sequence analysis and homology modeling. Differentially expressed genes(DEGs) were identified in rhizomes as compared to other tissues(flowers, leaves or roots).The 2 437 unigenes annotated by KEGG showed rhizome-specific expression, of which 35 unigenes involved in the biosynthesis of steroidal saponins. Our results greatly extend the public transcriptome dataset of Polygonatum and provide valuable information for the identification of candidate genes involved in the biosynthesis of steroidal saponins and other important secondary metabolites.

[Transcriptome analysis of venom gland and identification of functional genes for snake venom protein in Agkistrodon acutus].

Agkistrodon acutus is a traditional Chinese herb medicine which has immunological regulation,anti-tumor,anti-inflammatory and analgesic effects,which is mainly used for the treatment of rheumatoid arthritis,ankylosing spondylitis,sjogren's syndrome and tumors. In order to excavate more important functional genes from A. acutus,the transcriptome of the venom gland was sequenced by the Illumina Hi Seq 4000,and 32 862 unigenes were assembled. Among them,26 589 unigenes were mapped to least one public database. 2 695 unigenes were annotated and assigned to 62 TF families,and 5 920 SSR loci were identified. The majority of mapped unigenes was from Protobothrops mucrosquamatus in the NR database,which revealed their closest homology. Three secretory phospholipase A_2 with different amino acid sequences showed similar spatial structures and all had well-conserved active sites. The 3 D structural models of C-type lectin showed conserved glycosylation binding sites( Asn45). This study will lay the foundation for the further study of the function of snake venom protein,and promoting the development and utilization of genome resources from A. acutus.

[Cloning and characterization of chalcone synthase and chalcone isomerase genes in Arisaema heterophyllum].

Chalcone synthase( CHS) and chalcone isomerase( CHI) are key enzymes in the biosynthesis pathway of flavonoids. In this study,unigenes for CHS and CHI were screened from the transcriptome database of Arisaema heterophyllum. The open reading frame( ORFs) of chalcone synthase( Ah CHS) and chalcone isomerase( Ah CHI) were cloned from the plant by RT-PCR. The physicochemical properties,expression and structure characteristics of the encoded proteins Ah CHS and Ah CHI were analyzed. The ORFs of Ah CHS and Ah CHI were 1 176,630 bp in length and encoded 392,209 amino acids,respectively. Ah CHS functioned as a symmetric homodimer. The N-terminal helix of one monomer entwined with the corresponding helix of another monomer. Each CHS monomer consisted of two structural domains. In particular,four conserved residues define the active site. The tertiary structure of Ah CHI revealed a novel open-faced ß-sandwich fold. A large ß-sheet( ß4-ß11) and a layer of α-helices( α1-α7) comprised the core structure. The residues spanning ß4,ß5,α4,and α6 in the three-dimensional structure were conserved among CHIs from different species. Notably,these structural elements formed the active site on the protein surface,and the topology of the active-site cleft defined the stereochemistry of the cyclization reaction. The homology comparison showed that Ah CHS had the highest similarity to the CHS of Anthurium andraeanum,while Ah CHI had the highest similarity to the CHI of Paeonia delavayi. This study provided the basis for the functional study of Ah CHS and Ah CHI and the further study on plant flavonoid biosynthesis pathway.

Cloning, expression, and characterization of three ribosomal protein S13 genes in Sophora flavescens / Clonagem, expressão e caracterização de três proteínas ribossômicas S13 genes em Sophora flavescens

To characterize the structure and function of ribosomal protein S13 (RPS13), we identified fulllength open reading frames (ORFs) of three RPS13 genes (RPS13-1, RPS13-2, and RPS13-3) of the Chinese medicinal plant, Sophora flavescens. The target genes were amplified by reverse transcription-olymerase chain reaction (RT-PCR), ligated into the pET22b(+) vector, and then transformed into Escherichia coli BL21 competent cells for protein expression. The physicochemical properties, protein motif, evolution, and structural organization of the three RPS13 genes were analyzed using bioinformatics tools. The full-length ORFs (453 bp) of the three RPS13 genes of S. flavescens were cloned, and each encodes a protein of 151 amino acids in length, and their expression was detected by Western blotting. Bioinformatics analysis showed that RPS13s are stable proteins that are closely related to the 40S RPS13s of Vigna radiate var. radiate. Their three-dimensional structures included three -helices at the C-terminal and four -helices at the N-terminal, and the two clusters of helices were connected by a long random coil, which may help maintain the dynamic bridging interactions between the large and small subunits of the ribosome. The full-length ORFs of three RPS13 genes of S. flavescens were successfully cloned and expressed in vitro. The study of the physicochemical properties, evolution, and secondary and three-dimensional structures of the three proteins will provide the theoretical basis for further studies on the function of RPS13s in plants.

Objetivo: Para caracterizar a estrutura e a função da proteína ribossomal S13 (RPS13), identificamos fases de leitura abertas (ORFs) completas de três genes RPS13 (RPS13-1, RPS13-2 e RPS13-3) da planta medicinal chinesa, Sophora flavescens. Métodos: Os genes alvo foram amplificados por reação em cadeia da polimerase por transcrição reversa (RT-PCR), ligados ao vetor pET22b(+), e então transformados em células competentes de Escherichia coli BL21 para expressão protéica. As propriedades físico-químicas, o motivo protéico, a evolução e a organização estrutural dos três genes RPS13 foram analisados utilizando ferramentas de bioinformática. Resultados: ORFs completos (453 pb) dos três genes RPS13 de S. flavescens foram clonados, e cada um codifica uma proteína de 151 aminoácidos de comprimento, e sua expressão foi detectada por western blotting. A análise de bioinformática mostrou que as RPS13s são proteínas estáveis que estão intimamente relacionadas com as 40S RPS13s de Vigna radiata var. radiate. Suas estruturas tridimensionais incluíam três -hélices no C-terminal e quatro -hélices no N-terminal, e os dois aglomerados de hélices eram conectados por uma longa bobina aleatória, o que pode ajudar a manter as interações de ponte dinâmicas entre o subunidades grandes e pequenas do ribossomo. Conclusões: As ORFs completas de três genes RPS13 de S. flavescens foram clonadas e expressas com sucesso in vitro. O estudo das propriedades físico-químicas, evolução e estruturas secundárias e tridimensionais das três proteínas fornecerão a base teórica para estudos adicionais sobre a função das RPS13s em plantas.

Risk of hemorrhage associated with co-prescriptions for Ginkgo biloba and antiplatelet or anticoagulant drugs.

OBJECTIVES: The aim of this study was to explore the risk of hemorrhage associated with co-prescriptions for Ginkgo biloba extract (GBE) and antiplatelet or anticoagulant agents, and evaluate the trends of co-prescriptions. METHODS: A retrospective population based study was performed by using claim data of the Taiwan National Health Insurance Research Database from 2000 to 2008. Prescriptions for GBE alone and in combination with antiplatelet/anticoagulant drugs were retrieved and the odds ratio for co-prescriptions after the first prescription of GBE was explored. RESULTS: The total number of prescriptions for GBE alone or in combination with antiplatelet or anticoagulant agents increased gradually from 1547 (0.08%) and 3575 (0.19%) in 2000 to 4676 (0.23%) and 15,297 (0.79%) in 2008, respectively. GBE was mostly prescribed to patients aged 60 years or older. The adjusted odds ratio for co-prescriptions associated with the risk of hemorrhage is 1.5 (95% confidence interval, 0.5-5.0). The risk of hemorrhage was associated with patients aged ≥65 and male patients, who were prescribed GBE alone (adjusted odds ratio: 3.8 and 1.4; 95% confidence interval, 2.8-5.2 and 1.1-1.9). CONCLUSIONS: Although the combination of G. biloba extract with antiplatelet or anticoagulants showed insignificant correlation to the risk of hemorrhage, patients using ginkgo, particularly those with known bleeding risks and elderly, should take a particular attention to the possibility of increasing risk of bleeding.